Optical Time Domain Reflectometers (OTDRs) have been widely used for verification of performance characteristics of optical networks. To obtain OTDR measurements, a series of OTDR pulses are injected into optical fibers under test, and returned light from the optical fibers is measured as a function of time. Using the OTDR measurements, fiber problems (e.g., fiber loss, fiber cut) can be localized. Conventionally, standalone OTDR equipment with dedicated components have been utilized to perform the OTDR measurements. However, the dedicated components lead to increased size and cost, and limit the capability to easily deploy and test fiber spans. Integration of OTDR with other optical components may meet these challenges. However, the integration of OTDR with other optical components is difficult because noise from the other components may interfere with the OTDR measurements. Therefore, there is a need to provide improved OTDR functionality.